Sheet metal clamp



April 1943. 1 F. c. WALLACE 2,439,531

SHEET METAL CLAMP Filed Nov. 27, 1944 2 Sheets-Shet l E1 53 Y 6 I .4

April 1 3, 1948. E Q WALLACE 2,439,531

- SHEET METAL CLAMP Filed Nov. 27, 1944 2 Sheets-Sheet 2 INVENTOR. .Ii'l" fink LI, LU czfficz DL-I' Patented Apr. 13, 1948 SHEETMETAHGLAMP llranki 6.. Wallace North Hollywood; Calm, as;

ner. to Herman H Helhush,., Los Ains ljesi.

(ialif.

Application: November 27, 1944, Serial! NG-u 56.53116 5i-Claims. (Cl;,85i-'-5l) present invention; relates to sheet metal clamps, of. the txpeadapted t'fl bfl inserted in, registerlngt perforations. in superimposed. sheets; to-

temporarily clamp t-he sheets together with the holes; im alinement.

In general; such clamps utili-zs; a tubiilan body: having ant and wall: presentinga: sheet engaging; surface and through an: axial opening in which walla retaining; Din reciprocates, the; being; urged retractedbymeans: of" a; compression spring in thebody. Theouter'end of= the-.retainingpin is enlarged tot provide a; shoulder which serves as v the other sheet-engaging member in. use. aretaining pin is inserted through: registering; holes intwow or more. superimposed work. sheetsand: the

sheets are resiliently clamped bBlJW8ILl3hQ6E body able: towards and away from thepworlvengagiha shoulderprovidediby thefOlltfili end portionofqt'hes retaining pin.

Another novel-characteristic oi my invention resides in the construction which; renders it suitable for exerting unusually high clamping; nressureslwithout injuringL the work: sheets;

Anotherobject of the invention residesxin the novelandi efiicient means 1 by which mount the: retaining pins in the plunger element.

An additional objectvis the provision in such a clamp of improved means for retaining the spreader bar inthe body.

Another object of the invention is theprovision in such a clamp of means of nrotractinglthe re: taining pins against th pressure of the retracting spring without useof a separate tool.

Those familiar with the, art; will observe still furthen features of novelty and advantage: by reading; the following detailed description on a presently preferred embodiment of the invention which I illustrate in theaceompanving drawings, it being; understood, of' course, that within; its broader. scope as defined-i by; the annexed: claims, my invention is capable-of being embodiedin other physical forms differing specifically from the adaptation now to be described.

In the accompanying drawings Fig. 1 is a longitudinal section;

Figs. 2, 3, 4 and 5 are sectional views taken on lines 2-4, 3-3, 44, 5-5, respectively, of Fig. 1;

disa perspective of an end; portion or the clampwiththe adj usting sleeve, look nut. and the, retaining, member. removed;

Fig. Z isalongitudinal section showing the. retaining member protracted; and

Fig. 8 is aside elevation showing, the device in clamping position...

The. numeral, denotes a body having a longitud-i-nal borer ii presenting an enlarged diameter inner orright-handend portion 6a providing a shoulder 1;, 7

Each endot the body is externally threaded and n its. inner end 1 thread, asap 9 av n -an xi opening; lit of smaller diameterthan the; bore ea.

n the 011G6 7 end; of th I threadedlv mount a sleeve having an; endwall l6 presenting; an; axial opening H. A. loch nut H3 is also threadedlymounted on, the body for locking engagement with-the inner end of the sleeve l5.

ReciprocallvmQunted in the bore, 6; there is a retaining member comprisinga plunger whose inner endihas sliding fitinthebore 5 andwhose reduced externally threadedshank portion 21- is threaded into a socket, 22 in thestemportion-25a The. latter portionhas a headed outer end.- 24 which isengaged by one endof compressionspring 5. The' pp sit ncir fp th p in bears against-thershoulder-l.

Alsdforming part oi the retaining member provide a pair of opposite vdisp sedretain ns pins having their respective inner ends fitting in a so ket in the. inn rd of plun er Zltthe p ns havin a rally inwardly p oj tin inn r end portions 32 which engage behind a cross pin 33. extending t roug the: sides of the: plunger to hold the retaining pins inthe socket; The re? taming p ns project:outward vvthrous he op n leftehandt nd-oi t ebo y andithmu heop nmg; H in e s fi veandiwall it, having enlargementsr35 at: their; outerends. to provide shoulders 359 facin the end wall It! The pins 3c are protraotable andiretraotable through the end wall lfi un nmovem nt i he plun er andare adapt d o e inserted: th ou h; isterin perforations (see: Figs and; 8):, the: outer surlace; othe: en wall !6" bearin against: the djacent surface. or: one of thetworki sheets and he: shoulders 36 en aging he adjacent surface of the-othershdfit: (see; Fig. 8'), so thatthe sheets are: clamped. between the shoulders: at and the end wall [6.

Each of the retaining pins has a beveled inner surface 40 and to spread the pins apart I provide a T-shaped spreader bar having a central 7 leg 45a and a cross arm 45b. The spreader bar is secured in the body between the retaining pins by means of a snap ring 48 which fits in a complementary groove in the bore 6. The outer or left-hand end of the body 5 is provided with diametrically opposite longitudinal slots 50 into which the cross arm of the spreader fits, the inner ends of the slots providing a stop to prevent inward longitudinal movement of the spreader bar relative to the body and the snap ring serving as a stop to prevent outward longitudinal movement of the spreader bar.

In Fig. 1 the headed right-hand end 24 of the plunger is shown as abutting the inner surface of the cap 9, thus preventing any further retractive movement of the retaining pins. If the work sheets S to be clamped together have a combined thickness of, say, one-half inch, the sleeve 15 is jectin outwardly through said opening, and a '15 rotated until it occupies the desired position of adjustment for such thickness, which position will be indicated by registration of the appropriate indicia of the scale 55, provided on at least one of the retaining pins, with the outer surface of the end wall. The plungeris then moved inwardly of the body by a conventional clamp-operating tool, not shown, which tool has a portion entering the opening at to engage and push inwardly on the head 24 while the clamp body is held against longitudinal movement by a portion of the clamp-operating tool engaging in the annular recess 57 provided between the ends of the clamp body, This inward movement of the plunger will protract the retaining pins 38 until the beveled surfaces 48 of the pins pass over the outer end of the leg 45a of the spreader bar (Fig. '7). The retaining pins Will spring together so that their enlarged outer ends may be inserted through the registering perforations P in the work sheets. By then releasing the inward pressure on the plunger. the spring 25 will retract the retaining pins until the shoulders 36 engage the outermost work sheet around the perforation,

the retainin pins then having been again spread apart by riding back over the outer end of the stationary spreader bar (Fig. 8).

By virtue of the adjustable sleeve it is possible to prevent any injury to the work sheets S in case the spring 25 is strong enoughto exert enough clamping force to tend to imbed the shoulders 36 or the end wall I6 in the surface at the work sheets, because by adjusting the sleeve 15 the clamp will securely hold the sheets together but will not tend to draw the enlarged ends 35 of the pins through the perforations.

I claim:

1. A sheet metal clamp comprising a body having a longitudinal bore, a sleeve threaded on the outer end of the body for axial adjustment relative thereto, said sleeve having an end wall providing a sheet-engaging surface and presenting an axial opening, a retaining member reciprocally mounted in the bore for protraction and retraction through said opening, said retaining member having a pair of laterally expansible pins each presenting a lateral projection at its outer end providing a sheet-engaging shoulder facing said end wall, a spreader member stationarily carried by the body and disposed between said pins for laterally spreading said pins apart upon retractive movement of the retaining member, and spring means foracting between the 4 body and retaining member to exert retractive pressure on the latter.

2. The clamp of claim 1 wherein the body presents a pair of diametrically opposite longitudinal slots in its outer end portion and wherein said spreader member is mounted in said slots and disposed between the pins.

3. The clamp of claim 1 wherein the body presents a pair of diametrically opposite longitudinalslots in its outer end portion and. wherein said spreader member is disposed between the pins and having a cross arm portion mounted in said slots and a central elongated portion prosnap ring carriedby the body in position to prevent outward escape of the cross arm portion of the spreader bar from the slots.

4. A sheet metal clamp comprising a body having a longitudinal bore, a sleeve threaded on the outer end of the body for axial adjustment relative thereto, said sleeve having an end wall providing a sheet engaging surface and presenting an axial opening, a retaining member reciprocably mounted in the bore for protraction and retraction through said opening, said retaining member comprising a plunger slidably mounted in the bore, a spring urging the plunger into retracted position, said plunger presenting a socket in its inner end, a pair of oppositely disposed pins having laterally disposed inner ends mounted in said socket and a cross pin mounted in the plunger and extending across said socket between the inner end portions of the pins, and a spreader member stationarily carried by the body for spreading engagement with the oppositely dis- POSEd pins.

5. A sheet metal clamp comprising a body having a longitudinal bore, a sleeve threaded on the outer end of the body, said sleeve havin an outer end wall providing a sheet engaging surface and presenting an axial opening, a plunger mounted to reciprocate in the bore of the body, said plun er carrying a retaining member projecting outwardly through said opening and having a lateral portion disposed in opposed relation to the work-engaging surface of the sleeve whereby to engage work therebetween, spreader means fixed to the body and disposed to engage and laterally move the retaining member upon movement of the plunger inwardly of the body, and spring means carried by the body and cooperating with the plunger to urge the latter inwardly of the body, said sleeve being axially adjustable relative to the body.

FRANK C. WALLACE.

REFERENCES CITED Great Britain Oct.' 22, 194$ 

